1. Field of the Invention
This invention relates to a flat V-bed knitting machine with improved knocking over bits.
The new knocking over bits are intended for use in a flat V-bed knitting machine fitted with a presser foot which is located between the knocking over bits of the two needle beds and holds down the knitted fabric from above, as opposed to the operation of conventional take-down rollers which pull down the fabric from below the needle beds.
2. Description of the Prior Art
When holding down rib fabrics, the presser foot acts on the yarn extending between the needles of the opposite needle beds in the machine and thus a narrow presser foot acting in a central region between the needle beds is satisfactory, or even advantageous. However, in order to hold down fabric knitted on a single bed of needles, the presser foot must act on loops of yarn located close to the knocking over bits of the needle bed and in fact extending, in each case, from a needle, around the front (inner) edge of an adjacent knocking over bit to an adjacent needle. Presser feet having a rectangular cross-section and wide enough to come close to the knocking over bit edges have been used for knitting single bed fabrics but have been found to have limitations with regard to the range of stitch lengths which can be knitted with a presser foot of given dimensions even if the inner edges of the opposite presser feet are made parallel to one another.
One reason for the difficulties which have arisen has been found to be that, as close examination shows, the gap between the opposed needle beds of a machine, and thus between the opposite, inner edges of the knocking over bits does not remain constant along the whole length of the needle beds but is subject to a slow variation as one moves along the needle bed. That is, the periodicity of the variation in the gap along the needle beds is long in relation to the length of a presser foot (which is approximately 10 cm). Thus, a presser foot at a fixed height in relation to the knocking over bits will at some positions along the needle beds come close to or touch the knocking over bits and at other positions will be spaced further from the knocking over bits.